The topic of the 29th Hosbach Colloquium Energy Transduction in Biological Membranes is one of the most formidable problems in biology. Its solu- tion in molecular terms has proved to be a very difficult task for a whole generation of biochemists. The Mosbach Colloquia had so far not yet covered this subject. In for- mer Mosbach Colloquia some contributions were closely related, such as the lecture by E. C. Slater on the mitochondrial respiratory chain, presented 25 years ago. A broader coverage of this subject was given in the Mosbach Colloquia on Biochemistry of Oxygen in 1968, and on...